1. Field of the Invention
The present invention generally relates to a cable assembly, and particularly to a cable assembly having a plurality of circuit boards for high speed signal transmission.
2. Description of Related Art
With the development of communication and computer technology, high density electrical connectors are desired to construct a plurality of signal transmitting paths between two electronic devices. Each of these electrical connectors provides a plurality of circuit boards to thereby achieve improved signal transmission of different electrical characteristics through the connector. Such high density electrical connectors, such as cable assemblies, are widely used in internal connecting systems of severs, routers and the like requiring high speed data processing and communication.
U.S. Pat. No. 6,217,364 (the ""364 patent), issued to Miskin et al., discloses a cable assembly including an insulating housing formed by a pair of substantially identical housing halves and a high-speed electrical cable including a plurality of wires terminated to conductive terminals overmolded in a plurality of thin flat wafers, The housing halves combine to define an interior cavity having a front opening and a rear opening. The wafers are closely juxtaposed in a parallel array and are positioned within the interior cavity of one of the housing halves such that the cable projects out of the rear opening of the cavity. The other housing half is then to completely enclose the cable and wafer subassembly. However the cable and wafer subassembly are retained in the housing by securing the housing halves together through bolts and nuts, thereby complicating the assemblage of the cable assembly. Furthermore, an engagement of the housing halves is easy to become loose due to vibration during the transportation and other matters, whereby the cable and the wafer subassembly cannot be stably retained in the housing. Thus, an electrical connection is adversely affected between the cable assembly and a complementary connector.
U.S. Pat. Nos. 5,924,899 (the ""899 patent) and 6,102,747 (the ""747 patent), both issued to Paagman, each disclose a cable assembly. Referring to FIGS. 4a-4c and 5a-5c of the ""899/""747 patent, the cable assembly includes an insulating housing with a plurality of parallel slots defined therein and a plurality of modules received in the slots of the housing. Each module includes a circuit substrate, a receptacle carrier having a plurality of fork contacts at one end of the substrate and an insulation displacement contact (IDC) carrier at the other end of the substrate opposite the terminal carrier. The insulation displacement carrier has insulation displacement contacts connecting with conductors of corresponding cables. The modules each are retained in the housing through an interference fit with the housing. When the cable assembly is required to disengage from a complementary connector, a pulling force is exerted on an exposed end of the cable for releasing the engagement between the cable assembly and the complementary connector. However, the modules may be pulled back with regard to the housing, thereby adversely affecting an electrical engagement when the cable assembly mates with the complementary connector again. Furthermore, an additional device is employed to bond the cables together, thereby increasing the cost of the production.
A drawback occurred in the ""899 patent, the ""747 patent and the ""364 patent is that when it is desired for both high-speed signals and low-speed signals transmitted in a same cable assembly, the inventions disclosed in all the instant mentioned patents could not be applicable for all the patents are designated for transmitting only high-speed signals.
Hence, an improved cable assembly is highly desired to overcome the disadvantages of the related art.
Accordingly, it is an object of the present invention to provide a cable assembly having strain relief means for substantially resisting a pulling force exerted on a cable thereof.
It is another object of the present invention to provide a cable assembly having a plurality of high-speed cables and a plurality of low-speed cables connecting to circuit boards thereof.
In order to achieve the above-mentioned objects, a cable assembly in accordance with the present invention for engaging a complementary connector comprises an insulating housing, a pair of outer circuit modules positioned in opposite sides of the housing, a plurality of inner circuit modules sandwiched between the outer circuit modules, and a two-piece cover cooperating with the housing for retaining the circuit modules. Each outer circuit module includes a circuit board accommodated in the housing and a plurality of high-speed cables terminated to the circuit board. Each inner circuit module includes a circuit board, a pair of high-speed cables for transmitting differential pairs of signals, and a plurality of low-speed cables extending between and parallel to the two high-speed cables for transmitting single-ended signals. Each circuit module also has a cable clamp bonding the cables.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.